The present invention relates to an ink jet printer and, more particularly, to a novel optical ink jet head which generates gas by irradiation of a photochemically reactive substance by visible rays, ultraviolet rays, X rays or like active electromagnetic waves so as to eject ink by the pressure of the gas.
Well known in the printing art is an ink jet printer which ejects drops of ink from an ink jet head toward a paper to print out desired information on the paper. In prior art ink jet printers, the ejection of ink drops has been implemented by various types of ink jet heads such as an electric field on-demand type, a magnetism on-demand type, an on-demand type using an inorganic electrostrictive element, and a bubble type producing bubbles by thermal pulses to cause ink drops to be ejected by the expansion pressure of the bubbles. All such prior art ink jet heads are driven by electrical signals and not directly driven by optical signals.
Remarkable progress recently achieved in the optical communications art has made it possible to transmit and receive signals which contain various kinds of information over optical fibers or the like. Concerning such optical communications, it is preferable that received optical signals be directly stored in a storage or printed out by a printer without being converted into electrical signals. Especially, in relation to the application of an ink jet printer as the printer described, there is an increasing demand for a capability of reproducing information directly from optical signals which convey the information.